/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/ViewModels/HierarchyEditor/NiagaraUserParametersHierarchyViewModel.h
For editing in the details panel we want to handle the script variable that is represented by the hierarchy item, not the hierarchy item itself.
virtual [UObject](API\Runtime\CoreUObject\UObject\UObject) * GetDataForEditing()